I saw a posting for "private viewings." can someone explain what they are, and how I find out where they are.  If there are ads, how do I recognize them ?

Thanks

where you can sit and see a disrobed gal, who is usually playing with herself or otherwise being titillating in some fashion, and you can jerk off to this sight.

I don't know where to find this service myself, but I bet a few hours on the internet would yeild some kind of results.

Perhaps try the ISO board.